Update hrsc links

datasets/MEX/HRSC/README.md

@@ -3,6 +3,11 @@
 HSRC data are available at different processing levels.
 As explained in [Scholten et al., 2005] (hereafter S05):
 
+* Ortho and DTM data: https://pds.nasa.gov/ds-view/pds/viewDataset.jsp?dsid=MEX-M-HRSC-5-REFDR-DTM-V1.0
+* PDS node: https://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm
+
+* HRSC user guide: https://ode.rsl.wustl.edu/mars/pagehelp/quickstartguide/index.html?hrsc.htm
+
 * Level-1: conversion of original data stream (transmitted to ground) to de-compressed data;
 * Level-2: radiometric correction of the image data;
 * Level-3: map projection of all data;
@@ -30,6 +35,3 @@ and a FTP at ftp://psa.esac.esa.int/pub/mirror/MARS-EXPRESS/HRSC/ .
 [Scholten et al., 2005]: Scholten_etal_2005-HRCS_Data_Processing.pdf
 [S05 Fig-1]: Scholten_etal_2005-Fig1_Technical_Params_HRSC_SRC.png
 
-
-available at:
-* 

datasets/MEX/README.md

@@ -2,6 +2,8 @@
 
 ESA/PSA portal about Mars Express: https://www.cosmos.esa.int/web/psa/mars-express
 
+* PDS node: https://pds-imaging.jpl.nasa.gov/portal/mex_mission.html
+
 Articles:
 * [Spacecraft and Pyload Data Hanling](Zender_etal_2009-MEX_Payload_Data_Handling.pdf)